Q&A column, 2/15
February 2015—Can our laboratory use ALK immunohistochemistry in lung adenocarcinoma to select patients for targeted therapy? ALK gene rearrangements (the most common of which results in expression of the EML4-ALK fusion protein) are found in approximately five percent of lung adenocarcinomas, and these ALK-rearranged tumors show marked clinical response to the tyrosine kinase inhibitor crizotinib.